<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>JS文件的引入</title>
    <!-- 内部js -->
    <script type="text/javascript">
        alert('Javascript从入门到实战');
    </script>
    <!-- 引入外部js -->
    <script type="text/javascript" src='js/index.js'></script>
</head>
<body>
    
</body>
</html>